Heretofore, in the event that a driver becomes unable to drive due to a sudden illness or the like during his or her driving a vehicle, an accident may be caused. Therefore, to prevent accidents by detecting such driving incapability state of a driver has been proposed.
A drive control apparatus described in Patent Literature 1 detects pressing force of buttocks on the seat portion of a driver seat, pressing force of back on a seat back, and pressing force of left foot on a floor, and on the basis of the pressing forces distribution, the drive control apparatus determines whether the driver's posture is a normal posture, forward inclining posture, or backward inclining posture. When the driver's posture is a forward or backward inclining posture, the drive control apparatus determines that something wrong with driver's physical condition.
In an emergency refuge-seeking apparatus described in Patent Literature 2, various information is acquired from, for example, a sight line or face direction measurement device, thereby recognizing the driver's condition, such as degree of deterioration of driver's consciousness, degree of driver's awakeness, or driver's posture. When a driver's state declines, emergency refuge-seeking assistance is provided. The sight line or face direction measurement device captures an image of a driver by means of a driver camera and recognizes items of information about, for example, driver's sight line, blinking, and face direction from the captured image.
The inventors of the present application have found the following. Not only when the driver's posture inclines forward or backward due to his or her having a sudden illness or the like, but also when the driver picks up an object on a front passenger seat during driving, the driver's posture may collapsed, resulting in similar pressing forces distribution as in the case of sudden illness. In the apparatus described in Patent Literature 1, posture collapse, caused by factors other than driver's seizure or the like, are not taken into account. Therefore, the device may erroneously detect driver's driving incapability.
In addition, the inventors of the present application have found the following. In the event that a driver has a sudden illness or the like during his or her driving, direction of the driver's face may collapse. However, direction of the driver's face may collapse also when the driver drives looks aside during driving, for example. In the apparatus described in the Patent Literature 2, collapse direction of a face, caused by factors other than deterioration of driver's consciousness, sudden illness, or the like, are not taken into account. Therefore, the device may erroneously detect driving incapability state of a driver.